Back pain at 5 weeks 1 day

I found out I was pregnant only 3 days ago (of course we're both overjoyed!) and have been suffering with quite bad back pain since yesterday. I am tall and suffer with back pain in general anyway but this appears to be constant aches and trapped nerves in my back. Anyone else experiencing this? Does it settle or do I need to prepare for total back-breaking pain as I get further along?!!